Development of an automated in-line microfiltration system coupled to an HPLC for the determination of solubility.

An automated in-line microfiltration system coupled to an HPLC was developed for the determination of solubility. Filtrations and subsequent solubility determinations are performed using a standard Gilson dilutor and autosampler and dual Rheodyne valves equipped with a filtration assembly and configured to an HPLC system. The solubility data obtained using the automated in-line microfiltration system are in good agreement with the results obtained using conventional manual preparation techniques. Automating this labor-intensive and often variable portion of the solubility determination provides a reliable means of improving both the consistency and quality of solubility data.

Lymphangiomas of the oral cavity: a clinicopathologic, immunohistochemical, and electron-microscopic study.

PURPOSE: This study evaluated the demographics, treatment outcomes, histology, and basement lamina characteristics of a large series of lymphangiomas. MATERIAL AND METHODS: Forty-seven lymphangiomas of the oral cavity were evaluated microscopically and representative specimens were also evaluated immunohistochemically (IMH) and by electron microscopy (EM). RESULTS: Patient's ages ranged from 2 to 84 years. The dorsal surface of the tongue was the most common site. Discontinuities in the basement membrane were detected with IMH and EM. CONCLUSION: The discontinuous basement membrane may explain why sclerosing agents have not been effective as a form of treatment for lymphangioma.

Structural investigation of (1-methylimidazole)-2,3,7,8,12,13,17,18-octaethylporphinatozinc( II).

[Zn(C36H44N4)(C4H6N2)], [Zn(OEP)-(1-MeIm)], Mr = 680.26, monoclinic, P2(1)/n, Z = 4, F(000) = 1448, a = 14.099 (3), b = 17.762 (2), c = 14.475 (2) A, beta = 95.48 (1) degrees, V = 3608.4 A3, T = 294 +/- 1 K. The calculated and observed densities are 1.25 and 1.26 g cm-3. 5700 observed reflections (measured with Mo K alpha radiation, lambda = 0.71073 A) were used to refine the structure to a final R1 = 0.072 and wR = 0.098. The complex crystallizes isomorphously with [Co(OEP)(1-MeIm)] and similarities and differences in side-chain disorder and core conformations are described. The average Zn-Np bond distance is 2.068 (7) A and the axial Zn-N(Im) distance is 2.106 (4) A. The zinc(II) atom is displaced 0.42 (1) A from the porphyrin mean plane. The 1-methyl-imidazole ligand plane makes a dihedral angle of 10.5 degrees with a Zn-Np vector. This orientation of the 1-methylimidazole ligand corresponds well with that of previously determined imidazole metalloporphyrin structures and further indicates that the preferred orientation of imidazole ligands is essentially insensitive to the dn configuration of the metal ion of the metalloporphyrin.